At least our rivers don’t light on fire anymore. Inspired by a well-publicized fire on the Cuyahoga River in 1969, the passage of the Clean Water Act in the US led to huge reductions in water pollution. Despite those positive strides, maintaining water quality requires ongoing attention. A new survey of streams and rivers, performed by the EPA, provides a greater sense of the scale of the challenge. While industrial pollution, like mercury, remains a concern, agricultural runoff, in the form of sediment and fertilizers, is now far more widespread.

Water quality monitoring is performed by states using a variety of methods, which can make it difficult to accurately compile the national picture. The US Environmental Protection Agency has started carrying out nation-wide surveys to provide consistent, standardized snapshots of water quality. Following on the heels of the 2006 Wadeable Streams Assessment, the EPA recently released a draft comprehensive survey of streams and rivers.

The legwork was carried out in 2008 and 2009 by 85 crews that visited 1,924 sites in the lower 48 states. The sites were selected at random using an algorithm that ensured a representative sample. At each site, crews evaluated the stream’s surroundings, inventoried the species present, and collected samples for chemical analysis.

To turn all this data into a simplified assessment of stream health, ratings of “good”, “fair”, and “poor” were assigned. The tricky part is settling on a definition of what constitutes “good”. Good relative to its neighbors? Or what it could be if human impacts were limited? Or what it was like before human modification?

The EPA group settled on a “best of what’s left” approach. After breaking the country into nine regions based on landscapes and ecosystems, they identified a number of “least disturbed” sites in each—streams that were, on the whole, least affected by human activities. They then noted the range of the test results for those sites. If, to use phosphorus as an example, the concentration measured in a given stream was higher than 75 percent of the “least disturbed” sites, it would be considered “fair”. If it was higher than 95 percent of the “least disturbed” sites, it would be “poor”.

The survey looked at several physical indicators of stream quality, such as the condition of the riparian zone beside the stream, the amount of sediment washing into the stream, and the quality of fish habitat (like hiding places). Along 15 percent of the roughly 1.2 million miles of streams and rivers in the contiguous United States, excess sediment is problematic—blanketing the streambed with fine mud and clogging up the nooks and crannies many organisms rely on. Nearly a third of streams were rated as having fair or poor fish habitat.

Excess nutrients—from agricultural runoff or sewage treatment plants—can really do a number on water bodies. Apart from empowering ecosystem take-overs by invasive species, high nutrient levels can cause massive blooms of algae. The decay of those algae—once they die—can use up oxygen and suffocate fish. The survey found that 28 percent of the nation’s stream length has high concentrations of nitrogen, and fully 40 percent has too much phosphorus.

But what do the organisms themselves show? The crews collected fish, algae, and invertebrates (like insects and mollusks) to see which species were present. Diversity is a good sign, as is the presence of species known to be sensitive to various types of pollution. Nationally, just 21 percent of streams were in good biological condition for invertebrates, while 55 percent were in poor condition. The American West was in better shape—about 42 percent of streams were in good condition—but the rest of the country dragged down the average, with only about 17 percent of streams in good condition.

The numbers for fish and algae were slightly better—for each, about 40 percent of streams were good and 40 percent were poor.

So what can we do to work towards healthier streams? The EPA group analyzed the data for the characteristics that were most widespread and had the greatest biological impact—the problems that provide the biggest levers on water quality improvement. Three stood out: nitrogen, phosphorus, and excess sediment. For example, sampling locations with high phosphorus were 50 percent more likely to be in poor biological condition. By reducing the amount of sediment and these nutrients in streams, we could see noticeable gains in stream water quality.

The assessment also considered two factors with direct human health impacts: mercury and fecal pathogens. Mercury—which is released from things like coal-burning power plants—in fish is a widespread problem that dictates the health advisories on how much fish anglers can safely eat. The mercury sampling was relatively limited—characterizing only 51,500 miles of streams. But along a quarter of those stream miles, the amount of mercury in fish exceeded the EPA safety standard for average fish consumption.

Bacteria associated with fecal material were present above levels EPA considers safe in 9 percent of streams. The bacteria themselves aren’t the problem so much as the difficult-to-measure pathogens that accompany them. Those pathogens sometimes shut down public beaches, but warnings aren’t available for other places where people may wade or swim.

In order to squeeze the most value out of this data, EPA will have to repeat this effort to monitor changes over time. The next round of sampling is scheduled for 2013-2014. In the meantime, streams aren’t the only surface water bodies getting attention—similar assessments for the nation’s lakes, wetlands, and coastal waters are underway. Surveys like this can motivate action (who wouldn’t like to see healthier waters and fish that don’t need mercury warnings?) but they can also guide that action by prioritizing which problems to tackle first. While there’s good news in these reports, there is also clearly room for improvement—and when it comes to water quality, the bar should be set pretty high.

Ars Science Video >

A celebration of Cassini

A celebration of Cassini

A celebration of Cassini

Nearly 20 years ago, the Cassini-Huygens mission was launched and the spacecraft has spent the last 13 years orbiting Saturn. Cassini burned up in Saturn's atmosphere, and left an amazing legacy.

42 Reader Comments

The followup Mercury numbers in a few years should be interesting. Despite extensive attempts to block it, old coal plants lost their grandfathered status on mercury emissions last year; and are required to reduce their emission rates by 90% by 2017 (some plants are being shut down instead of spending hundreds of millions on upgrades). Roughly half of the Mercury pollution in the US is believed to be from domestic sources and coal plants are one of the largest offenders; so this should cut the amount being released significantly. I don't know how long it lingers in the local environment though.

This is the number one problem I have with the Global Warming debate. Knee jerk reactions tend to cause more harm than good. Hey, the globe is warming, we need a better fuel for our cars and stuff. I know, let's use corn. Demand for corn goes up; farmers grow corn year round to meet demand; don't rotate crops to reduce the need for fertilizers; dump tons of nitrogen into the soil....etc.

Note, I'm not trying to start a Global Warming debate, just saying that we need to understand that our "solutions" can easily do more harm than good when we don't take the time to consider the ramifications.

Nice coverage of this, and yet there's so little information out there about Columbia river and millions of gallons of leaking radioactive waste right on its shores in SE Washington state. Hanford is the biggest potential environmental disaster in the US.

If this is the first survey, how is it known that ag runoff has increased?

XavierItzmann wrote:

Since 40% of the corn crop is wasted on ethanol, the greens/tree huggers are responsible a significant chunk of needless river and lake pollution.

Hypocritical hyenas.

Ethanol has changed corn from an energy crop into a protein crop. Reducing the demand for soybeans. Net food production remains unchanged. Corn provides more ground protection than soybeans. People ignorant like you are the trouble.

While there’s good news in these reports, there is also clearly room for improvement

It is good to see we have actually been having success cleaning up some pollutants in our waters. Agricultural contamination is another hurdle we are researching and working on, and not many people realize how bad of a problem sedimentation is. Thanks for the story.

Water quality exists on a continuum from 'OMG water so polluted it catches on fire!' to 'pure enough to drink'.

Now while most everyone will agree that water really shouldn't burn and that being able to drink anywhere would be great, what about the cost? Trying to make every river and stream in America carry water safe enough to drink would bankrupt us! No we just need to get to 'good enough' and we're basically there. We need to look at the regulations already in place and drop those that are only incrementally improving the water but costing businesses millions. Incremental improvement cost more for every increment and we've improved our waterways enough already, and probably have way too many regulations that aren't doing anything but costing us unnecessarily. You wan't manufacturing to come back to this country we need to stop onerously putting all these regulations on our entrepreneurs.

Since 40% of the corn crop is wasted on ethanol, the greens/tree huggers are responsible a significant chunk of needless river and lake pollution.

Hypocritical hyenas.

The drivers for increased ethanol production were primarily 1) concerns over energy independence and security (i.e., not relying on foreign oil) and 2) finding a way to prop up agribusiness. Environmental concerns, if they came up at all, weren't given priority. Most greens and tree-huggers that I know share your disdain for ethanol production.

+1We do not Support this nor do we Support Monsanto Garbage !And meanwhile the Corrupted Politicians have plenty of Converts to sucking more money while destroying the Future.

What does Monsanto have to do with this? I thought the majority of Mercury run off was caused by coal power plants?

Don't get me wrong; I despise Monsanto more than most, but this isn't an article about aggressive GMO crops.

Edit: Ah it seems DanNeely beat me to the punch

I think the shot about Monsanto was intended to be a stawman; but I don't really get the connection unless the intent was just to point at a poster child for unpopular big-agriculture to try and imply that pollution not caused by the power companies was more important without actually trying to defend them.

Water quality exists on a continuum from 'OMG water so polluted it catches on fire!' to 'pure enough to drink'.

Now while most everyone will agree that water really shouldn't burn and that being able to drink anywhere would be great, what about the cost? Trying to make every river and stream in America carry water safe enough to drink would bankrupt us! No we just need to get to 'good enough' and we're basically there. We need to look at the regulations already in place and drop those that are only incrementally improving the water but costing businesses millions. Incremental improvement cost more for every increment and we've improved our waterways enough already, and probably have way too many regulations that aren't doing anything but costing us unnecessarily. You wan't manufacturing to come back to this country we need to stop onerously putting all these regulations on our entrepreneurs.

/rhetoric

That about what you expect? Probably not strong enough.

Except that it encompasses more than just water potability. We are also talking about biodiversity! Do we really need to encumber our businesses with regulations to save nonessential species such as MacFuddington's Darter*, or the Striped Toejam Mussel*, or the Virginia Clearwater Bastard Salamander*?

/sarcastic rhetoric

Sedimentation and algal blooms are big problems when it comes to aquatic ecosystems.

Since 40% of the corn crop is wasted on ethanol, the greens/tree huggers are responsible a significant chunk of needless river and lake pollution.

Hypocritical hyenas.

Actually, most "greens" I know do not support ethanol. It's just a huge give away to farmers and other vested interests. But nice try.

"It's just a huge give away to farmers and other vested interests." Exactly. It's the same reason there's high fructose corn syrup in the vast majority of American food products. Big Corn is almost as powerful as Big Oil. Almost.

«The Obama Administration has set a goal of making 10,000 new flex-fuel pumps available to America’s drivers within the next five years – a five-fold increase from today’s level. And today, I am visiting Minnesota where there are over 360 stations pumping E-85 – more than any other state. It is time for the rest of the nation to follow their lead.»

And here I thought the tree huggers were all about "weaning us off of oil" via biofuels.

Heh.

Tie yourself in knots, greenie.

I'm confused as to who you mean by 'greenie' and 'tree hugger'. You should properly define your terms here since you are basically saying nothing. You should also read up about bio-fuels, there are two major variants. First generation biofuels (those made from a crop that is specifically grown for making biofuel) and second generation (those made with crop by products).

First generation is basically just shooting yourself in the foot from a sustainability standpoint since in many cases it takes more energy to produce the crop in the first place when you consider energy needs of farming equipment. The corn and soy biofuels are only making money because of large government subsidies.

Second generation is better, but I still find biofuels as an awful stop gap for what is going to be a world wide transportation energy crisis. Second generation biofuels will probably mostly be used for plastics when those start to get expensive. Plastic is in everything and not all of is easily recyclable.

We're having the same issues down here in New Zealand as the government finds way to boost our economy through increased agricultural production - the sad reality is that what we need to actually do is move up the value chain so that higher value products are exported rather than just milk powder and big chunks of meat. Although there have been some trials of chemicals and introducing certain insects, I think the real long term solution is to move always from intensive farming in the case of NZ.

In the case of the United States the issue can be put at the feet of agricultural subsidies - over production of goods that artificially depress prices which necessitate more production, it is a vicious cycle.

This is the (or a) next frontier in improving how we farm. The move to Organic certification has been important for consciousness-raising (what am I eating, where does it come from) but it is very human-centric. The next step is additive -- to farm more holistically with thought towards the entire ecosystem and here certification movements like Fish Friendly Farming (http://www.fishfriendlyfarming.org) are a move in the right direction.

I heard that there are reports indicating we have over 100,000 different type of chemical fertilizers in our farmlands compares to other nations' 10,000. Don't know if this numbers are any accurate. Even 10,000 sounds high. Farm fish and farm chicken and eggs are off my list. But now reading this, fresh fish may not be that safe after all. What am I going to eat next? Oh I know, grow my own?

«The Obama Administration has set a goal of making 10,000 new flex-fuel pumps available to America’s drivers within the next five years – a five-fold increase from today’s level. And today, I am visiting Minnesota where there are over 360 stations pumping E-85 – more than any other state. It is time for the rest of the nation to follow their lead.»

Barack Obama pushing for ethanol bolsters the very point you're trying to debunk: that environmentalists, and people who care at all about the environment, are not the ones pushing for ethanol.

«The Sierra Club, the League of Conservation Voters, Environment America and Clean Water Action have jointly endorsed President Obama in his reelection bid»

You gotta love the tree huggers trying to walk back on their record and pretending that the ethanol boondoggle is not the result of their scaremonging. Just like the greenies of 40 years ago who killed nuclear (the cleanest, CO2-freest power source) and then spent the last decade whining about global warming.

Since 40% of the corn crop is wasted on ethanol, the greens/tree huggers are responsible a significant chunk of needless river and lake pollution.

Hypocritical hyenas.

Actually, most "greens" I know do not support ethanol. It's just a huge give away to farmers and other vested interests. But nice try.

I think it would be more accurate to say that green groups do not support ethanol produced from corn, which is probably the most wasteful and least green way to do it, primarily because of the need for extensive fertilizer to grow corn. Without federal subsidy, corn would be a much less profitable crop and would occupy a much smaller portion of our diet and economy.

Barack Obama pushing for ethanol bolsters the very point you're trying to debunk: that environmentalists, and people who care at all about the environment, are not the ones pushing for ethanol.

«The Sierra Club, the League of Conservation Voters, Environment America and Clean Water Action have jointly endorsed President Obama in his reelection bid»

They did, as opposed to Mitt Romney. Not out of all of the presidential candidates. Green groups are useless when it comes to elections. They're great at keeping you updated at local developments, and terrible at anything to further their own causes long-term. A candidate who endorses fracking, offshore drilling, oil pipelines that have every reputable scientist hyperventilating, and "clean coal" as our energy future is by no means an environmentalist.

Quote:

You gotta love the tree huggers trying to walk back on their record and pretending that the ethanol boondoggle is not the result of their scaremonging. Just like the greenies of 40 years ago who killed nuclear (the cleanest, CO2-freest power source) and then spent the last decade whining about global warming.

Ethanol fuel has been a boon to the business community, not the environment. Even if you argue it's a "result" of "scare mongering" about the environment, it doesn't change the fact they at no point pushed for it. It was an easy legislative win, and for Congress and oil companies to say "see, we're trying" without actually accomplishing anything meaningful. And I'm sure many would be much more pro-nuclear if the safety standards were not only much more stringent, but actually upheld, unlike the current NRC. Radioactive isn't clean, nor healthy.

Barack Obama pushing for ethanol bolsters the very point you're trying to debunk: that environmentalists, and people who care at all about the environment, are not the ones pushing for ethanol.

«The Sierra Club, the League of Conservation Voters, Environment America and Clean Water Action have jointly endorsed President Obama in his reelection bid»

You gotta love the tree huggers trying to walk back on their record and pretending that the ethanol boondoggle is not the result of their scaremonging. Just like the greenies of 40 years ago who killed nuclear (the cleanest, CO2-freest power source) and then spent the last decade whining about global warming.

Barack Obama pushing for ethanol bolsters the very point you're trying to debunk: that environmentalists, and people who care at all about the environment, are not the ones pushing for ethanol.

«The Sierra Club, the League of Conservation Voters, Environment America and Clean Water Action have jointly endorsed President Obama in his reelection bid»

You gotta love the tree huggers trying to walk back on their record and pretending that the ethanol boondoggle is not the result of their scaremonging. Just like the greenies of 40 years ago who killed nuclear (the cleanest, CO2-freest power source) and then spent the last decade whining about global warming.

Ever heard of "the lesser of two evils"? He's better than the tea party....

I'd argue that he's worse. When a party leader has moved the discourse so "liberal" or "centrist" is the dirtiest possible energy plan short of demolishing and outlawing any development, private or public, of clean energy initiatives, we would have been better off with a President doing the same things Obama is, but that liberals would actually object to because he's not on their "team." Maybe then there'd be a true and more powerful movement to a more efficient and cleaner future.

Even if you argue it's a "result" of "scare mongering" about the environment, it doesn't change the fact they at no point pushed for it.

If you scream "fire" in a crowded theater, it does not change the fact that at no point you trampled any dead people.

The environmentalists made their noise about the fierce moral urgency of biofuels back in the 1990's and now they own this calamity, fair and square.

Raising awareness for an issue and offering concrete solutions (solar, wind, hydro, etc) for this issue does not make you culpable if somebody says "based on my awareness of this, let's do something completely different." That's a terrible analogy. A better one would be somebody in a theater remarking "I wonder if this theater's maximum capacity is exceeding fire code" and somebody, upon hearing that, chains the doors shut and tosses a lit match.